Historical mosquito colonization dynamics drive patterns of microbial community assembly in aboveground aquatic habitats

Mosquito larvae develop in aquatic habitats that harbor highly variable communities of bacteria and other microorganisms that have been well demonstrated to shape individual fitness outcomes in the laboratory. However, relatively little is known about how this variation contributes to or is shaped by variation in mosquito population dynamics in the field. To investigate the effects of mosquito population dynamics on microbial community assembly, we characterized bacterial communities in naturally occurring larval habitats with variable historical mosquito productivity using amplicon sequencing. We then used a null model approach to quantify the relative importance of selection, dispersal, and drift processes on bacterial community assembly. Habitat microbiota clustered into two distinct biotypes, with communities in Biotype 1 being dominated by members of the Proteobacteria and communities in Biotype 2 being dominated by members of the Cyanobacteria. Both biotype communities were structured by selection and neutral (i.e., dispersal and drift) processes. However, selection was more important in habitats harboring Biotype 1 communities, while drift was more important in habitats harboring Biotype 2 communities. Variation partitioning further identified the drivers of selection to be changes in historical mosquito productivity measures and the spatial aggregation of sites with similar productivity histories. Overall, this study casts new light on the ability of mosquitoes to shape aspects of their environment that are important for their fitness and lays the foundation for future studies to understand how patterns of microbiota diversity and mosquito occurrence and/or abundance could be integrated into vectorial capacity models to better predict mosquito-borne disease transmission dynamics in the field.